This invention is directed to the measurement of thicknesses of insulating glass units.
Thicknesses of installed glass units are the most perplexing problem to glass replacements specialists and estimators.
When estimating replacement of insulated glass units having broken or damaged glass or seals, cost may vary widely according to the thicknesses of the glass units. Fixed estimates may result in reduction or loss of profits, or in actual negative profits. Overestimations may result in loss of contract awards and reduction of jobs.
When a job is awarded based on an estimate, the estimators measurements of thickness and areas may be accepted, or a skilled glass installer may remeasure the job for precise requirements when ordering materials. While the square areas may be measured with precision, it is often difficult to measure glass thicknesses with the same precision. If the thickness is miscalculated, losses may be incurred when ordering nonreturnable special sizes, or when ordering wrong standard sizes. Delays are encountered and installation expenses are increased when insulating units of the wrong thickness are assembled and delivered to job sites.
Calipers have been available to measure glass thickness, but the calipers are limited in lateral expanse. Many buildings with insulated glass do not have windows that open to permit insertion and engagement of the calipers, and thus the calipers are useless. Many doors are separated from windows by greater dimensions than the length of the calipers, again rendering the calipers useless.
Devices with mirrors on opposite sides of the window and viewing scopes for looking through the window toward a mirror at predetermined angles and lining up marks on the angular devices have been offered with mixed reception. Difficulties of seeing images in the devices and understanding the use of the devices sufficiently to avoid mistakes in their use have prevented widespread acceptance or use of such devices.
A need persists for a simple device with simple indications that can be easily and assuredly read for measuring thicknesses of insulating glass units.